Semiconductor device

ABSTRACT

An object of the invention is to make it possible to perform the embedding of a Cu diffusion preventing film and a Cu film to a fine pattern of a high aspect ratio by using a medium of a supercritical state in a manufacturing process of a semiconductor device. The object of the invention is achieved by a substrate processing method comprising a first step of processing a substrate by supplying a first processing medium containing a first medium of a supercritical state onto the substrate, a second step of forming a Cu diffusion preventing film on the substrate by supplying a second processing medium containing a second medium of a supercritical state onto the substrate, and a third step of forming a Cu film on the substrate by supplying a third processing medium containing a third medium of a supercritical state onto the substrate.

TECHNICAL FIELD

The present invention relates to a substrate processing method and asemiconductor device manufacturing method, and further relates to amethod of depositing a metal film.

BACKGROUND ART

In recent years, high integration of semiconductor devices progresseswith high performance of semiconductor devices, and the demand of finewiring patterns is increasing. The wiring rule on the order of 0.13 to0.10 micrometers or less is under development. And, aluminum (Al) as theconventional wiring material has been substituted for by copper (Cu)which has a low resistance with little influence of wiring delay.

Therefore, the combination of the Cu film formation technology and thefine wiring technology serves as an important key technology for themultilevel interconnection technology in recent years.

The sputtering method, the CVD method, the plating method, etc. aregenerally known as the above mentioned method for film deposition of Cu.However, when taking into consideration the fine wiring technology, eachmethod has a limited coverage, and it is very difficult to form a Cufilm efficiently in a fine pattern which is at a high aspect ratio of0.1 micrometer or less.

Then, as a method of efficiently forming a Cu film in a fine pattern, amethod for film deposition of Cu using a medium of a supercritical stateis proposed (see “Deposition of Conformal Copper and Nickel Films fromSupercritical Carbon Dioxide”, SCIENCE vol. 294, Oct. 5, 2001,www.sciencemag.org).

According to the literature “Deposition of Conformal Copper and NickelFilms from Supercritical Carbon Dioxide”, a Cu film formation precursorcompound (precursor) which contains Cu is dissolved using CO2 of asupercritical state, and a Cu film is formed.

The term “supercritical state” means that the substance concerned is inthe state of having the features of a gas and a liquid, when thetemperature and pressure of the substance concerned become beyond avalue (critical point) peculiar to the substance concerned.

For example, in the above-mentioned medium using CO2 of thesupercritical state, the Cu film formation precursor which is theprecursor compound containing Cu has a high solubility but has a lowviscosity and a high diffusibility, and the Cu film formation isattained in a fine wiring pattern of a high aspect ratio.

The embedding of Cu to a fine pattern is introduced in the aboveliterature “Deposition of Conformal Copper and Nickel Films fromSupercritical Carbon Dioxide”.

However, when actually creating a semiconductor device by theabove-mentioned Cu film formation, it is necessary to form the diffusionpreventing film of Cu between Cu and an insulating layer, in order toprevent diffusion of Cu to the inside of the insulating layer betweenthe Cu wirings, for example.

It is known that any of a metal film, a metal nitride film or alaminated film of a metal film and a metal nitride film may be used asthe Cu diffusion preventing film, and the metal is chosen from a groupincluding Ti, Ta, W, TiN, TaN, WN, etc.

The sputtering method has been conventionally used for formation of theabove-mentioned Cu diffusion preventing film. However, it is difficultto provide a sufficient coverage for a fine pattern of the recentsemiconductor devices, and the sputtering method has such difficulty.

In recent years, the CVD method which provides a good coverage has beenused in many cases instead of the sputtering method. However, thecurrent situation is that if it is applied to a fine pattern of a highaspect ratio of 0.1 micrometers or less, the coverage of the CVD methodis also inadequate.

Moreover, when formation of a Cu film using the medium of asupercritical state is considered, a decompression process is requiredin addition to a pressurization process for the sputtering method or theCVD method, and it is necessary to prepare two kinds of devices withdifferent configurations. Further, it is necessary to convey a substratebetween a pressure reduction device and a pressurization device, andthere is a problem that the productivity is low.

DISCLOSURE OF THE INVENTION

A general object of the present invention is to provide a new and usefulsubstrate processing method and semiconductor device manufacturingmethod in which the above-mentioned problems are eliminated.

A more specific object of the present invention is to provide asubstrate processing method which enables the embedding of a Cudiffusion preventing film and a CU film in a fine pattern of a highaspect ratio by using a medium of a supercritical state.

In order to achieve these objects, the present invention provides asubstrate processing method comprising: a first step of processing asubstrate by supplying a first processing medium containing a firstmedium of a supercritical state onto the substrate; a second step offorming a Cu diffusion preventing film on the substrate by supplying asecond processing medium containing a second medium of a supercriticalstate onto the substrate; and a third step of forming a Cu film on thesubstrate by supplying a third processing medium containing a thirdmedium of a supercritical state onto the substrate.

According to the above-described invention, it is possible to performboth the formation of a Cu diffusion preventing film and the embeddingof a Cu film using a medium of a supercritical state.

Since the solubility of the precursor compound containing a metal (forexample, Cu or Ta) in the medium of the supercritical state is high, andthe precursor compound is rich in mobility and its diffusibility ishigh, even in a very fine pattern, the formation of the Cu diffusionpreventing film and the embedding of the Cu film can be performed.

Moreover, if the above-described substrate processing method is appliedto a semiconductor device manufacturing method, it is possible toperform both the formation of a Cu diffusion preventing film and theembedding of a Cu film in a semiconductor device by using a medium of asupercritical state.

Since the medium of a supercritical state has the high solubility of theprecursor compound containing a metal (for example, Cu or Ta) and theprecursor compound is rich in mobility and its diffusibility is high,even in a very fine pattern, the formation of the Cu diffusionpreventing film and the embedding of the Cu film can be performed, andthe manufacture of a semiconductor device having a fine pattern isattained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing the process flow of the substrate processingmethod according to the invention.

FIG. 2 is a diagram showing the composition of the substrate processingdevice which performs substrate processing according to the invention.

FIG. 3 is a diagram showing the process flow of the substrate processingmethod according to the invention.

FIG. 4 is a diagram showing the process flow of the substrate processingmethod according to the invention.

FIG. 5 is a diagram showing the process flow of the substrate processingmethod according to the invention.

FIG. 6 is a diagram showing the process flow of the substrate processingmethod according to the invention.

FIG. 7 is a diagram showing the process flow of the substrate processingmethod according to the invention.

FIG. 8 is a diagram showing the process flow of the substrate processingmethod according to the invention.

FIG. 9 is a diagram showing the process flow of the substrate processingmethod according to the invention.

FIG. 10A is a diagram showing the saturated-vapor-pressure curve of Cufilm formation precursor, and

FIG. 10B is a diagram showing the partial pressure of Cu film formationprecursor in CO2 of a supercritical state.

FIG. 11 is a diagram showing the process flow of the substrateprocessing method according to the invention.

FIG. 12 is a diagram showing the process flow of the substrateprocessing method according to the invention.

FIG. 13 is a diagram showing the process flow of the substrateprocessing method according to the invention.

FIG. 14 is a diagram showing the process flow of the substrateprocessing method according to the invention.

FIG. 15 is a diagram showing the process flow of the substrateprocessing method according to the invention.

FIG. 16 is a diagram showing the process flow of the substrateprocessing method according to the invention.

FIG. 17 is a diagram showing the process flow of the substrateprocessing method according to the invention.

FIG. 18A, FIG. 18B and FIG. 18C are diagrams showing the semiconductordevice manufacturing method using the substrate processing methodaccording to the invention.

FIG. 18D, FIG. 18E and FIG. 18F are diagrams showing the semiconductordevice manufacturing method using the substrate processing methodaccording to the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

A description will now be given of the embodiments of the invention withreference to the accompanying drawings.

The First Embodiment

FIG. 1 shows the process flow of the substrate processing methodaccording to the invention.

In this process, the following steps are performed by using the CO2 ofthe supercritical state or the nitrogen compound of the supercriticalstate as described above.

As shown in FIG. 1, the substrate processing method comprises thecleaning of the surface of the processed substrate which is the firststep (step S100), the film formation of Cu diffusion preventing filmwhich is the second step (step S200), and the film formation of Cu filmwhich is the third step (step S300).

First, in the first step, the oxide film of Cu formed on the substrate(for example, on the surface of Cu film) is removed by using theprocessing medium with the etching agent dissolved in CO2 of thesupercritical state.

By removing the oxide film on the Cu film, it becomes possible to reducethe electric contact resistance (contact resistance) value of the Cufilm concerned and the Cu diffusion preventing film formed at thefollowing second step.

Next, in the second step, any of a metal film, a metal nitride film, ora laminated film of a metal film and a metal nitride film is formed as aCu diffusion preventing film on the Cu film surface which was cleaned inthe first step.

For example, when forming the laminated film of the metal film and themetal nitride film, the metal film is first formed by using theprocessing medium with the metal film formation precursor (which is theprecursor compound containing the metal) dissolved in CO2 of asupercritical state. Next, the metal nitride film is formed by using theprocessing medium with the metal film formation precursor dissolved inthe nitrogen compound of a supercritical state or the medium in whichCO2 of the supercritical state is mixed with the nitrogen compound ofthe supercritical state. At this process, using CO2 of the supercriticalstate or the nitrogen compound enables efficient formation of a Cudiffusion preventing film in a fine pattern.

At the third step, the Cu film is formed by using the processing mediumwith the Cu film formation precursor (which is the precursor compoundcontaining Cu) dissolved in CO2 of the supercritical state. At thisprocess, using CO2 of the supercritical state enables efficientformation of a Cu film in a fine pattern.

Next, the substrate processing device which performs the substrateprocessing method will be explained using the accompanying drawings.

The Second Embodiment

FIG. 2 shows the composition of the substrate processing device 500which can perform the substrate processing method according to theinvention.

As shown in FIG. 2, the substrate processing device 500 comprises anexhaust system including the processing container 501 having thesubstrate holding stand 501A in which the substrate heater 501 a isbuilt, the gas mixer 502 which supplies to the processing container 501the processing medium containing the medium of the supercritical statefor performing substrate processing, and the exhaust line 503 whichexhausts the processing container 501.

The semiconductor wafer W which is the processed substrate is laid inthe mounting base 501A. The processing medium containing the medium of asupercritical state from the gas mixer 502 is supplied to the processingcontainer 501, so that substrate processing is performed.

The processing medium concerned after the substrate processing isdischarged from the exhaust line 503 by opening valve 504, and theprocessing container 501 is almost in an atmospheric pressure state.

When exhausting the inside of the processing container 501 to below theatmospheric pressure, it is possible to carry out evacuation from theevacuation line 508 using the vacuum pump 507 by opening the valve 506and valve 538.

The gas mixer 502 which forms the processing medium and supplies theprocessing medium concerned to the processing container 501 is connectedto the processing container 501 via the supply line 510 in which thevalve 509 is attached.

By mixing the medium of a supercritical state and a predeterminedadditive in the gas mixer 502, the processing medium is formed, and theprocessing medium is supplied to the processing container 501.

The pressurization line 511 a to which the liquid CO2 supply unit 512 isconnected is connected to the gas mixer 502.

In the pressurization line 511 a, the valve 514 and valve 516 a areopened, and CO2 is supplied to the gas mixer 502 from the liquid CO2supply unit 512. In that case, the booster pump 517 a installed in thepressurization line 511 a is operated, so that CO2 being supplied to thegas mixer 502 is pressurized to the supercritical state.

The booster pump 517 a is cooled by the chiller so that the temperaturerise under operation may be suppressed and CO2 in the state of a liquidmay be pressurized.

In addition, NH3 may be supplied to the gas mixer 502 from the liquidNH3 supply unit 513 by opening the valve 515 and valve 516 b in thepressurization line 511 b. In that case, the booster pump 517 binstalled in the pressurization line 511 b is operated so that NH3supplied to the gas mixer 502 is pressurized to the supercritical state.

The booster pump 517 b is cooled by the chiller so that the temperaturerise under operation may be suppressed and NH3 in the state of a liquidmay be pressurized.

It is also possible to generate the medium of the supercritical state inwhich CO2 of the supercritical state and NH3 of the supercritical stateare mixed, by opening the valves 514 and 516 a and the valves 515 and516 b. The valves 514 and 516 a and the valves 515 and 516 b may beopened simultaneously. Alternatively, the valves 514 and 516 a may beopened first, or the valves 515 and 516 b may be opened first.

A heater is installed in the gas mixer 502, the processing container501, the supply line 510, a part of the pressurization line 511 a, apart of the pressurization line 511 b, the valve 516 a, and the valve516 b. They are heated and CO2 and NH3 are set in a supercritical stateexceeding a critical point. The area of the substrate processing device500 where the heater is installed and the heating is performed to createthe supercritical state is indicated by the area 501B in FIG. 2.

Moreover, the liquid material supply line 518, the solid material supplyline 519, and the gas supply line 520 are connected to the gas mixer502. The liquid material, the solid material, and the gas arerespectively dissolved in or mixed with the medium of the supercriticalstate, so that the processing medium is created and it is supplied tothe processing container 501.

The liquid material supply line 518 will first be explained. The liquidmaterial supply line 518 is connected to the liquid material container521 holding the liquid material 523. The liquid material container 521is pressurized by the inert gas supplied from the gas line 522 linked tothe inert gas supply unit which is not illustrated. The liquid material523 concerned is supplied to the gas mixer 502 from the liquid materialsupply line 518 by opening the valve 523.

In that case, the liquid material 523 supplied is adjusted to apredetermined flow rate by the mass flow rate controller 524 installedin the liquid gas supply line 518. The supplied liquid material 523 ismixed with the medium of the supercritical state in the gas mixer 502,and it is supplied to the processing container 501.

The solid material supply line 519 will be explained next. The solidmaterial supply line 519 supplies the solid material 526 a or 526 bwhich is dissolved in CO2 which is the medium of the supercriticalstate, to the gas mixer 502 with the medium of the supercritical stateconcerned.

First, the feeding method of the solid material 526 a will be explained.The valve 528 a and the valve 514 are opened beforehand, and CO2 issupplied to the solid material container 525 a from the liquid CO2supply unit 512 via the pressurization line 511 a. In that case, thebooster pump 517 a installed in the pressurization line 511 a isoperated so that CO2 supplied to the solid material container 525 a ispressurized to the supercritical state.

The processing medium in which the solid material 526 a is dissolvedenough in CO2 which is the medium of the supercritical state is createdbeforehand. Then, the valve 527 a is opened and the processing mediumconcerned is supplied to the gas mixer 502 which is filled beforehandwith the medium of the supercritical state. The processing mediumsupplied to the gas mixer 502 is supplied to the processing container501 from the supply line 510 by opening the valve 509.

As for the solid material 526 b, similarly, the valve 528 b and thevalve 514 are opened beforehand, and CO2 is supplied to the solidmaterial container 525 b from the liquid CO2 supply unit 512 via thepressurization line 511 b. In that case, the booster pump 517 binstalled in the pressurization line 511 b is operated, so that CO2supplied to the solid material container 525 b is pressurized to thesupercritical state.

The processing medium in which the solid material 526 b is dissolvedenough in CO2 which is the medium of the supercritical state is createdbeforehand. Then, the valve 527 b is opened and the processing mediumconcerned is supplied to the gas mixer 502 which is filled beforehandwith the medium of the supercritical state. The processing mediumsupplied to the gas mixer 502 is supplied to the processing container501 from the supply line 510 by opening the valve 509.

Next, the gas supply line 520 will be explained. The H2 supply line 529in which the valve 530 is attached, and the etching agent supply line531 in which the valve 532 is attached are connected to the gas supplyline 520, and the gas supply line 520 can supply H2 and the etchingagent to the gas mixer 502, respectively. The H2 and the etching agentsupplied are mixed with the medium of the supercritical state in the gasmixer, and it is supplied to the processing container 501.

Thus, the substrate processing device 500 can perform substrateprocessing by using the processing medium in which the solid material,the liquid material, or the gas is dissolved in or mixed with the mediumof the supercritical state.

The pressurization lines 511 a and 511 b are connected to the processingcontainer 501 via the preliminary pressurization line 535 in which thevalve 540 a or 540 b is attached. Hence, it is possible to raise thepressure of the processing container 501 via the preliminarypressurization line 535 concerned without passing through the gas mixer502.

The pressure open valves 536, 537 a, and 537 b are installed in the gasmixer 502, the pressurization line 511 a, and the pressurization line511 b, respectively, for the purpose of preventing the abnormal rise ofthe pressure.

The processing container 501 is adjusted to a predetermined pressurethrough the exhaust line 503 by the back pressure regulating valve 504,it is possible to prevent the abnormal rise of the pressure.

Next, the process flow when the substrate processing method according tothe invention is performed using the substrate processing device 500will be explained.

The Third Embodiment

As described above, the substrate processing method according to theinvention comprises the first step, the second step, and the third step.

Next, the detailed flow of each of the first through third steps will beexplained using the drawings. However, the elements which are the sameas corresponding elements explained previously are designated by thesame reference numerals, and a description thereof will be omitted.

FIG. 3 shows the process flow of the contents of the first step in thethird embodiment.

As shown in FIG. 3, the first step of the substrate processing method ofthis embodiment comprises steps 101 to 107 (indicated as S101 to S107 inthe drawing).

The processing of the wafer W laid in the substrate holding stand 501Ais performed. In step 101, the valves 506, 534, and 538 are opened, andevacuation of the processing container 501 and the gas mixer 502 isperformed by the vacuum pump 507.

The valves 506, 534, and 538 are closed after the termination ofevacuation concerned. Alternatively, evacuation of the gas mixer 502through the processing container 501 may be performed by opening thevalve 509 without opening the valve 534.

Next, in step 102, the valve 514 and the valve 540 a are opened, and CO2is supplied to the processing container 501. In that case,pressurization is performed using the booster pump 517 a, and the area501B including the processing container 501 and the gas mixer 502 isheated by the heater. Thus, CO2 in the processing container 501 is madein the condition that the critical point of CO2 concerned is exceeded.

Moreover, the booster pump 517 a is cooled by the chiller. The CO2 isprevented from becoming a gas, and the CO2 in a liquid state ispressurized.

At the critical point, the temperature of CO2 concerned is 31.03 degreesC., and the pressure thereof is 7.38 MPa. The temperature and pressureof the processing container 501 is controlled to above the criticalpoint concerned, and the processing container 501 is in the state thatis filled with CO2 of the supercritical state.

Then, the valve 514 and the valve 540 a are closed. Thus, the inside ofthe processing container 501 is filled with CO2 of the supercriticalstate beforehand, and when the processing medium containing CO2 of thesupercritical state is subsequently introduced into the processingcontainer 501, the processing medium concerned can be maintained in thesupercritical state, and the processing medium of the supercriticalstate dissolved in a high concentration can be maintained.

When the processing container 501 concerned is set at the predeterminedpressure, the wafer W is heated by the substrate heater 501 a, and it ismade at the temperature in a range of 200 degrees C. to 400 degrees C.

Next, in step 103, by opening the valve 532, the etching agent issupplied to the gas mixer 502 of a decompression state from the etchingagent supply line 531, the inside of the gas mixer 502 is filled withthe etching agent concerned. After a predetermined time progresses, thevalve 532 is closed.

Next, in step 104, the valve 516 a is opened and the CO2 is introducedinto the gas mixer 502 and pressurized to the supercritical state withthe booster pump 517 a which is beforehand cooled with the chiller. Theetching agent is fully spread and mixed to form the processing medium.The valve 516 a is closed at a predetermined supercritical pressure.

Next, in step 105, the valve 509 is opened, and the processing mediumcontaining CO2 of the supercritical state is introduced into theprocessing container 501 from the gas mixer 502. Pressure regulation isperformed by opening and closing of the valve 516 a if needed, and theprocessing medium in the gas mixer 502 is conveyed to the processingcontainer 501.

Next, in step 106, substrate processing is performed by the processingmedium concerned. Preliminary pressurization to the supercritical stateof the processing container of step 102 may be performed between step104 and step 105.

For example, the reaction which removes a CuOx film formed in a Cusurface on the surface of the processed substrate takes place by theetching agent dissolved in CO2 of the supercritical state.

Concerning the by-product which is created after the reaction, the CO2of the supercritical state is easy to dissolve, and the reattachment tothe substrate does not take place.

The etching agent used may include a chelating agent, a halogenatedcompound, an acid, and an amine. Specifically,H(hexafluoroacetylacetonate) can be used as the chelating agent, HCl canbe used as the acid, and ClF3 can be used as the halogenated compound.Such etching agent removes the oxide film on the surface of Cu with theCO2 of the supercritical state.

Thus, it is possible to reduce the contact resistance of the Cudiffusion preventing film formed in the second step and the Cu film, byremoving the oxide film on the surface of Cu concerned.

Other etching agents that may be used include acetylacetone,1,1,1-trifluoro-pentane-2,4-dione, 2,6-dimethyl-pentane-3,5-dione,2,2,7-trimetyloxane-2,4-dione, 2,2,6,6-tetra-methylheptane-3,5-dione,EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid),acetic acid, formic acid, oxalic acid, maleic acid, glycolic acid,citrate, malic acid, lactic acid, amino acid, triethanolamine, etc.

Thus, in the step 106, it is possible to reduce the electric contactresistance (contact resistance) value of the Cu diffusion preventingfilm formed in the second step and the Cu film, by removing the oxidefilm on the surface of Cu concerned.

Next, in step 107, the valve 504 is opened, the processing medium andthe reaction secondary product in the processing container 501 and thegas mixer 502 are discharged, and the first step is ended.

After the step 107, as further shown in FIG. 4, a rinse process may beadded.

The Fourth Embodiment

FIG. 4 shows the modification of the third embodiment shown in FIG. 3.

In FIG. 4, the elements which are the same as corresponding elements inFIG. 3 are designated by the same reference numerals, and a descriptionthereof will be omitted. Namely, steps 101 to 107 in FIG. 4 are the sameas those in FIG. 3, and a description thereof will be omitted.

In step 108, the valve 504 is closed, the valve 516 a is opened, and theinside of the gas mixer and the processing container 501 is filled withCO2 of the supercritical state. After this, the valve 516 a is closed.

Then, CO2 of the supercritical state is discharged from the processingcontainer 501 and the gas mixer 502 by opening the valve 504 again instep 110.

It becomes possible to discharge the un-reacted processing medium andthe by-product adhering to the wafer W and the inner wall of theprocessing container 501, out of the processing container 501 byperforming the process of the steps 108 to 110.

The residue and the reaction secondary product described above can beremoved by returning from the step 108 to the step 107 at the step 109and repeating the rinse process of the steps 107 and 108 two or moretimes from the step 108, if needed.

The Fifth Embodiment

Next, the contents of the process flow of the second step will beexplained as the fifth embodiment.

The Cu diffusion preventing film is formed at the second step. Asdescribed above, the Cu diffusion preventing film comprises a metalfilm, a metal nitride film, or a laminated film of the metal film or themetal nitride film. In this embodiment, the case where the laminatedfilm of the metal film and the metal nitride film is formed will bedescribed.

Therefore, the formation process of the Cu diffusion preventing film inthis embodiment comprises a first half process which forms the metalfilm, and a second half process which forms the nitride film of themetal concerned.

The first half process of the second step is shown in FIG. 5.

With reference to FIG. 5, step 201 and step 202 are the same as the step101 and the step 102 described above. However, the wafer W is maintainedat 250 degrees C.-500 degrees C. by the substrate heater 501 a.

Next, in step 203, the solid material 526 a which is the Ta filmformation precursor held at the solid material container 525 a isintroduced into the gas mixer 502.

Before shifting to this step 203, the valves 514 and 528 a are openedbeforehand, and the solid material container 525 a is changed into apressurization state by CO2 using the booster pump 517.

The processing container 525 a is in the range of the area 501B, and itis heated with the heater, and therefore CO2 of the supercritical stateis generated within the solid material container 525 a.

Furthermore, CO2 of the supercritical state concerned has a highsolubility of the precursor, the solid material 526 a which is the Tafilm formation precursor (which is TaF5, for example) is fully dissolvedin CO2 of the supercritical state, and the processing medium is formed.

Thus, in this step 203, the valve 527 a is opened, and the processingmedium concerned are supplied to the gas mixer 502.

In order to maintain the pressure of the solid material container 525 ain that case, the valve 528 a is opened and closed, if needed.

After opening the valve 527 a for a predetermined time, the valve 527 ais closed.

Next, in step 205, the valve 509 is opened and the processing mediumconcerned which contains CO2 of the supercritical state from the gasmixer 502 is introduced into the processing container 501 from the gasmixer 502.

Pressure regulation is performed by opening and closing of the valve 516if needed, and the supercritical state of CO2 is maintained.

In the following step 206, film formation of Ta film is performed on thewafer W which is the processed substrate, and it shifts to the followingstep 207 after a predetermined time progresses.

In this step, the wafer W is maintained at 250 degrees C.-500 degrees C.by the substrate heater 501 a.

As described above, CO2 of the supercritical state has a high mobility,a very high solubility and a good diffusibility, and it enablesefficient formation of the metal film concerned on the bottom and sidewall of a fine pattern of 0.1 micrometer or less, and it is possible toacquire good coverage of the metal film on the pattern.

The following step 207 is the same as the step 107. In this embodiment,TaF₅ which is a halogenated compound is used as the Ta film formationprecursor. However, the same result is obtained even if any of TaCl₅,TaBr₅, and TaI₅ is used as a halogenated compound.

Even if any of (C₅H₅)₂TaH₃, (C₅H₅)₂TaCl₃, etc. is used as a precursor ofan organic metal, it is possible to obtain the same result.

The Sixth Embodiment

The fifth embodiment shown in FIG. 5 may be modified like the sixthembodiment shown in FIG. 6.

The process flow in the first half of the second step is shown in FIG.6. In FIG. 6, the elements which are the same as corresponding elementsin FIG. 5 are designated by the same reference numerals, and adescription thereof will be omitted.

The steps 208-210 in FIG. 6 are the same rinse processes as the steps108-110 described above, and it is similarly effective in removing theresidue and the reaction secondary product adhering to the inside of theprocessing container 501 or the wafer W.

The Seventh Embodiment

Next, the process flow in the second half of the second step is shown inFIG. 7.

The nitride film of the metal is formed in the second half process. InFIG. 7, the elements which are the same as corresponding elementsdescribed above are designated by the same reference numerals, and adescription thereof will be omitted.

The step 211 is the same as the step 101.

Next, in step 212, the valves 515 and 540 b are opened, and the gas of anitrogen compound, for example, NH3, is supplied to the processingcontainer 501. In that case, pressurization is performed using thebooster pump 517 b. Moreover, the area 501B including the processingcontainer 501 and the gas mixer 502 is heated with the heater. Thus, NH3in the processing container 501 is made in the condition which exceedsthe critical point of NH3.

At the critical point, the temperature of NH3 is 132.25 degrees C., andthe pressure thereof is 11.33 MPa. The temperature and pressure of theprocessing container 501 is controlled to beyond the critical pointconcerned, and the processing container 501 is in the state where it isfilled with NH3 of the supercritical state.

Thus, when the processing medium which contain NH3 of the supercriticalstate is subsequently introduced into the processing container 501 byraising the pressure in the processing container 501 beforehand, it ispossible to prevent the pressure of the processing medium concerned fromchanging rapidly.

After the processing container 501 concerned is at a predeterminedpressure, the wafer W is heated by the substrate heater 501 a, and thetemperature thereof is maintained at 250 degrees C.-500 degrees C.

The valves 515 and 540 b are closed after a predetermined timeprogresses.

Next, in step 213, the solid material 526 a which is the Ta filmformation precursor held at the solid material container 525 a isintroduced into the gas mixer 502.

Before shifting to this step 213, the valve 514 and the valve 528 a areopened beforehand, and the solid material container 525 a is changedinto a pressurization state by CO2 using the booster pump 517 a.

The processing container 525 a is in the range of the area 501B, and itis heated with the heater, so that CO2 of the supercritical state isgenerated within the solid material container 525 a.

Furthermore, CO2 of the supercritical state concerned has the highsolubility of the precursor, the solid material 526 a which is the Tafilm formation precursor (which is TaF5, for example) is fully dissolvedin CO2 of the supercritical state concerned, and the processing mediumis formed.

Then, in this step 213, the valve 527 a is opened, and the processingmedium concerned is supplied to the gas mixer 502.

In order to maintain the pressure of the solid material container 525 ain that case, the valve 528 a is opened and closed, if needed.

After opening the valve 527 a for a predetermined time, the valve 527 ais closed.

Next, in step 215, the valve 509 is opened and the processing mediumcontaining CO2 of the supercritical state from the gas mixer 502 isintroduced into the processing container 501 which is beforehand filledin the step 212 with NH3 of the supercritical state from the gas mixer502.

Pressure regulation is performed by opening and closing of the valve 516a, if needed, and the supercritical state in the processing container501 is maintained.

In the following step 216, film formation of a TaN film is performed onthe wafer W which is the processed substrate, and it shifts to thefollowing step 207 after a predetermined time progresses.

In the step 207, the wafer W is maintained at 250 degrees C.-500 degreesC. by the substrate heater 501 a.

As described above, NH3 of the supercritical state has a very highmobility and a good diffusibility, and it is possible to form the metalnitride film concerned efficiently on the bottom and side wall of a finepattern of 0.1 micrometer or less, and it is possible to acquire a goodcoverage of the film on the pattern.

The following step 217 is the same as the step 107.

In the present embodiment, the dissolution of the processing medium inthe solid material container 525 a, and the preliminary pressurizationof the processing container 502 are performed using CO2 of thesupercritical state, and the preliminary pressurization of theprocessing container 501 is performed using NH3 of the supercriticalstate. However, even if the medium of the supercritical state of themixed medium of NH3 and CO2 concerned is used, the same result isobtained.

In addition, the nitriding compound is not limited to NH3 but othernitrogen compounds can be used similarly.

The Eighth Embodiment

The seventh embodiment shown in FIG. 7 can be modified as in the eighthembodiment shown in FIG. 8. The process flow in the second half of thesecond step is shown in FIG. 8.

In FIG. 8, the elements which are the same as corresponding elementsdescribed above are designated by the same reference numerals, and adescription thereof will be omitted.

The steps 218-220 in FIG. 8 are the same rinse processes as the steps108-110, and it is effective in removing the residue which adhered tothe inside of the processing container 501, or the wafer W similarly andthe by-product.

Although, in the fifth through eighth embodiments, the example whichforms the laminated film of a metal film and a metal nitride film hasbeen shown as a Cu diffusion preventing film, the present invention isnot limited to this.

For example, what is necessary is just to skip the TaN film formationprocess which formed Cu diffusion preventing film only at the process ofthe fifth embodiment or the sixth embodiment, and was shown in theseventh embodiment or the eighth embodiment as a Cu diffusion preventingfilm, when forming the single layer film of Ta. Moreover, what isnecessary is just to skip Ta film formation process which formed Cudiffusion preventing film only at the process of the seventh embodimentor the eighth embodiment, and was shown in the fifth embodiment or thesixth embodiment, when forming the single layer film of TaN similarly.

The Ninth Embodiment

Next, the contents of the process flow of the third step are shown inFIG. 9 as the ninth embodiment. The third step is a process which formsCu film on the wafer W.

In order to form the Cu film concerned, the case where a solid materialis used as a Cu film formation precursor, and a liquid material may beused, but the process flow in the case of using a solid material isfirst shown in FIG. 9.

As shown in FIG. 9, steps 301 and 302 are the same as the steps 101 and102 first. However, wafer W is held by the substrate heater 501 a at 150degrees C.-400 degrees C.

Next, in step 303, after opening the valve 530 wide and carrying outgiven amount introduction of H2 from the H2 supply line 529 at the gasmixer 502, the valve 530 is closed. The gas mixer 502 is filled with theH2 concerned.

Next, in step 304, the solid material 526 b which is Cu film formationprecursor held at the solid material container 525 b is introduced intothe gas mixer 502.

First, in shifting to this step 304, the valves 514 and 528 b are openedbeforehand, and the solid material container 525 b is changed into apressurization state by CO2 using the booster pump 517 a.

The processing container 525 b is the range of the area 501B, and sinceit is heated with the heater, CO2 of a supercritical state is generatedwithin the solid material container 525 b.

Furthermore, since CO2 of the supercritical state concerned has the highsolubility of a precursor, solid material 526 b which is the Cu filmformation precursor and which is Cu+2 (hexafluoroacetylacetonate) 2, forexample fully dissolves in CO2 of the supercritical state concerned, andprocessing medium are formed in it.

Then, in this step 304, the valve 527 a is opened, and the processingmedium concerned are supplied to the gas mixer 502.

In order to maintain the pressure of the solid material container 525 bin that case, the valve 528 b is opened and closed if needed.

After opening the valve 527 b wide predetermined time, the valve 527 bis closed.

Next, in step 305, the valve 509 is opened and the processing mediumconcerned which contain CO2 of a supercritical state from the gas mixer502 are introduced into the processing container 501 from the gas mixer502.

Pressure regulation is performed by opening and closing of the valve 516if needed, and the supercritical state of CO2 is maintained.

In the following step 306, on the wafer W which is the processedsubstrate, the reaction represented by the following formula:Cu++(hfac)2+H2→Cu+2H(hfac)

where “hfac” denotes hexafluoroacetylacetonate takes place, and the filmformation of Cu film is performed.

It shifts to the following step 307 after predetermined time progress.In this step, the wafer W is maintained at about 150 degrees C.-400degrees C. by the substrate heater 501 a.

As described above, CO2 of a supercritical state has very high mobility,since it is rich in diffusibility, can form the Cu film concernedefficiently also on the fine bottom and fine side wall of 0.1 micrometeror less of a pattern, and can acquire the good coverage characteristicon them.

The following step 307 is the same as the step 107. The Cu filmformation precursor is even if it uses Cu+2(acetylacetonate)2, Cu+2(2,2, 6, and 6-tetra-methyl 3,5-heptanedione)2, etc. for others althoughCu+2(hexafluoroacetylacetonate) 2 was used in this embodiment. It ispossible to obtain the same result.

Some examples in which the Cu film formation precursor shows highsolubility to CO2 of a supercritical state are shown in FIG. 10A andFIG. 10B (FIG. 10A: R. E. Sievers and J. E. Sadlowski, Science 201(1978) 217, and FIG. 10: A. F. Lagalante, B. N. Hansen, T. J. Bruno,Inorg. Chem, 34 (1995))

FIG. 10A is the example of a saturated-vapour-pressure curve ofCu+2(hexafluoroacetylacetonate)2 which is the Cu film formationprecursor. For example, it is founded that the saturated vapour pressureat 40 degrees C. is about 0.01 Torr.

On the other hand, FIG. 10B is the example of the partial pressure ofCu+2(hexafluoroacetylacetonate)2 in the CO2 of a supercritical state at313.15K (40 degrees C.). For example, it is found that the partialpressure concerned at the time of 15MPa which is in a supercriticalstate is about 1000 Pa or higher, which shows that the density ofCu+2(hexafluoroacetylacetonate)2 existing in the CO2 of thesupercritical state is higher than that in the above-mentioned case ofthe usual saturation which is about 1000 Pa or more, which shows a veryhigh solubility.

Thus, the medium of a supercritical state having a high solubility withmobility and diffusibility, while the film formation rate is maintained,the film formation can be performed with good coverage of a fine wiringpattern.

The 10th Embodiment

The ninth embodiment can be modified as in the 10th embodiment which isshown in FIG. 11. However, the same referential mark is given to theportion explained previously among a diagram, and explanation isomitted.

Although the steps 308-310 in FIG. 11 are added with reference to FIG.11, the steps 308-310 are the same rinse process as the steps 108-110.And, the effect in which the residue and the by-product inside theprocessing container 501 or on the wafer W can be removed is attainedsimilarly.

The 11th Embodiment

Next, the example at the time of using a liquid material for Cu filmformation precursor is shown as an example of the process flow of thethird step.

FIG. 12 is a diagram showing the process flow of the third step at thetime of using a liquid material for Cu film formation precursor.

However, the same referential mark is given to the portion explainedpreviously among a diagram, and explanation is omitted.

As shown in FIG. 11, step 311 and step 312 are the same as the step 301and step 302. However, the wafer W is maintained at 100 degrees C.-350degrees C. with the substrate heater 501 a.

Next, in step 313, the liquid material 523 which is the Cu filmformation precursor Cu+1(hexafluoroacetylacetonate)(trimethylvinylsilane) is extruded by the inert gas, such as Ar, supplied from thegas lines 522, and is supplied to the gas mixer 502 of a decompressionstate from the liquid material supply line 518, and after apredetermined time is elapsed the valve 532 is closed.

Next, in step 314, the valve 516 is opened, CO2 of a supercritical stateis introduced into the gas mixer 502, and CO2 of the supercritical stateconcerned and the liquid material 523 are fully diffused and mixed, sothat the processing medium is formed. After a predetermined time iselapsed, the valve 516 is closed.

Next, in step 315, the valve 509 is opened, and the processing mediumconcerned containing CO2 of a supercritical state is introduced into theprocessing container 501 from the gas mixer 502.

Pressure regulation is performed by opening and closing of the valve 516if needed, and the supercritical state of CO2 is maintained.

In step 316, on the wafer W which is the processed substrate, thereaction represent by the following formulas:Cu+(hfac)(tmvs)→Cu+(hfac)+tmvs2Cu+(hfac)→Cu+Cu++(hfac)2

where “hfac” denotes hexafluoroacetylacetonate,

and “tmvs” denotes trimethylvinylsilane, takes place, and the filmformation of Cu film is performed.

It shifts to the following step 317 after a predetermined timeprogresses.

In this step, the wafer W is maintained at about 100 degrees C.-350degrees C. with the substrate heater 501 a.

As described above, CO2 of a supercritical state has very high mobility,since it is rich in diffusibility, can form the Cu film efficiently onthe fine bottom and fine side wall of 0.1 micrometer or less of apattern, and can acquire the good coverage characteristic on them.

The following step 317 is the same as the step 307.

In the present embodiment, as the Cu film formation precursor,Cu⁺¹(hexafluoroacetylacetonate) (trimethylvinylsilane) is used.Alternatively, a Cu film formation precursor which contains Cu⁺¹(hexafluoroacetylacetonate) and scillirolefinligand may be used, thescillirolefinligand being any chosen from among the following:allyl-oxytrimethylscillire(aotms), dimethyl acetylene(2-butyne),2-methyl-1-hexine-3-in (MHY), 3-hexine-2,5-dimethoxy(HDM),1,5-cyclooctadiene(1,5-COD), and vinyltrimethoxylene (VTMOS). Even whenthe alternative Cu film formation precursor is used, it is possible toobtain the same result.

The film quality of Cu film may be improved by adding the followingadditives to the processing medium used in this embodiment as follows.

For example, by adding H₂O to the processing medium, the incubation timeat the time of growing up Cu film on the Cu diffusion preventing filmdescribed above in the fifth through eighth embodiments can beshortened, and a substantial deposition rate can be raised. Moreover, byadding (CH3)I or (C2H5)I, when forming Cu film in a fine pattern, it ispossible to carry out the bottom-up filling (Kew-Chan Shim, Hyun-BaeLee, Oh-Kyum Kwon, Hyung-Sang Park, Wonyong Koh and Sang-Won Kang,“Bottom-up Filling of Submicrometer Features in Catalyst-EnhancedChemical Vapor Deposition”, J. Electorochem. Soc. 149(2) (2002)G109-G113). For example, even on via holes of 0.1 micrometer or less, aquality Cu film can be formed without creating void.

The 12th Embodiment

The 11th embodiment can be modified as in the 12th embodiment which isshown in FIG. 13. However, the same referential mark is given to theportion explained previously among a diagram, and explanation isomitted.

As shown in FIG. 13, the rinse process of steps 318-320 is added to theembodiment of FIG. 13, and this is the same as that of the steps 108-110in the previous embodiment. Similarly, the present embodiment providesthe effect which removes the residue and the by-product on theprocessing container 501 inside or the wafer W.

The 13th Embodiment

Although the first step, the second step, and the third step have beenexplained in the foregoing, the first through third steps are performedin the substrate processing device 500, which is shown in FIG. 14.

Although the first step, the second step and the third step (S100, S200and S300) which are carried out according to the invention are shown inFIG. 14, all the first through third steps surrounded by the region Aare performed in the substrate processing device 500.

It is possible to modify the processing method by using anothersubstrate processing device for this, as shown below.

FIG. 15 shows another embodiment of the substrate processing methodshown in FIG. 14.

For example, the first step shown in the region B is performed in thesubstrate processing device 500. Then, the processed substrate isconveyed to another substrate processing device, and the second stepshown in the region C is performed. Finally, the processed substrate isconveyed to another substrate processing device, and the third stepshown in the region D is performed.

Thus, it is also possible to perform the first through third stepscontinuously by conveying the processed substrate from one substrateprocessing device to another substrate processing device.

Another modification of the substrate processing method shown in FIG. 14is shown in FIG. 16 and FIG. 17.

However, the same referential mark is given to the portion explainedpreviously among a diagram, and explanation is omitted.

As shown in FIG. 16, the substrate processing device 500 performs thefirst and second steps shown in the region E, for example, the processedsubstrate is conveyed to another substrate processing device, and thethird step shown in the region F is performed.

As shown in FIG. 17, the substrate processing device 500 performs thefirst step shown in the region G, for example, and the processedsubstrate is conveyed to another substrate processing device.

When the first and second steps shown in the region H are performed, thesame result as in the case where the substrate processing device 500performs the first through third steps as shown in FIG. 14 is obtained.When conveying the processed substrate, not putting to the atmospherecontaining oxygen is important, and it is necessary to convey the bottomof decompression, or the inside of inert gas.

The 14th Embodiment

Next, the procedure of the manufacturing process of the semiconductordevice using the substrate processing method of the invention will beexplained with reference to FIG. 18A to FIG. 18F.

As shown in FIG. 18A, the insulating layer 601, such as a silicon oxide,is formed to cover the element (not shown), such as a MOS transistorformed on the semiconductor substrate which is made of silicon.

The element concerned is electrically connected to the wiring layer (notshown) which is made of W, and the wiring layer 602 which is made of Cu.These layers are connected to the element concerned and formed.

On the silicon oxide 601, the first insulating layer 603 is formed so asto cover the Cu layer 602. The groove part 604 a and hole part 604 b areformed in the insulating layer 603.

The Cu layer 604 which is a wiring layer is formed in the groove part604 a and hole part 604 b, and this layer is electrically connected withthe above-mentioned Cu layer 602.

The barrier layer 604c is formed in the contact surface of the firstinsulating layer 603 and the Cu layer 604, and in the contact surface ofthe Cu layer 602 and the Cu layer 604. The barrier layer 604c preventsthat Cu is spread from the Cu layer 604 to the first insulating layer603, and serves as the adhesion layer which raises the adhesion of theCu layer 604 and the first insulating layer 603.

The barrier layer 604c is made of the metal and the metal nitride filmconcerned, for example, Ta and TaN.

The second insulating layer 606 is formed so that the Cu layer 604 andthe first insulating layer 603 may be covered.

In this embodiment, the substrate processing method according to theinvention is applied to the second insulating layer 606, and the Culayer and the barrier layer are formed in it.

Next, as shown in FIG. 18B, the groove part 607 a and hole part 607 bare formed in the second insulating layer by the dry etching method.

Next, as shown in FIG. 18C, the first step of the substrate processingmethod according to the invention is applied.

As described above, the substrate surface is cleaned by using CO2 of thesupercritical state and the etching agent.

For example, the oxide film formed in the surface of the Cu layer 604exposed to the bottom of the hole part 607 b is removed, and theadhesion of the barrier layer formed at the following process and the Culayer 604 is raised.

It is effective in removing the residue matter and the by-product of theetching agent remaining inside the groove part 607 a and the hole part607 b.

Next, as shown in FIG. 18D, the second step according to the inventionis applied and the barrier layer 607 c is formed on the secondinsulating layer 606 top and the exposure side of the Cu layer 604.

For example, the barrier layer 607 c in this case is made of a Ta filmand a TaN film, and at the second step, as described above, the Ta filmis formed in the first half process, and the TaN film is formed in thesecond half process, so that the barrier layer 607 c which is made ofTa/TaN is formed.

As described above, in this process, CO2 and NH3 of the supercriticalstate are used, they have good diffusibility, and the barrier film 607 ccan be formed also in the bottom and wall part of the fine hole part 607b and the fine groove part 607 a with a good coverage.

Next, as shown in FIG. 18E, the third step according to the invention isapplied and the Cu layer 607 is formed on the barrier layer 607 c. Asdescribed above, the CO2 of the supercritical state is used in thiscase. Since CO2 of the supercritical state with the Cu film formationprecursor being dissolved has good diffusibility, the Cu layer 607 canbe formed in the bottom and wall part of the fine hole part 607 b andthe fine groove part 607 a with a good coverage.

Next, as shown in FIG. 18F, the Cu layer 607 upper part and the barrierfilm 607 c are ground by the CMP method, and the Cu wiring of the secondinsulating layer 606 is completed. After this process is performed, itis possible to further form the (2+n)th (n: a natural number) insulatinglayer in the upper part of the second insulating layer, and to form theCu wiring on each insulating layer with the application of the substrateprocessing method according to the invention.

It is possible to apply the invention also to formation of the barrierfilm 604 c and the Cu layer 604 which are formed in the first insulatinglayer.

INDUSTRIAL APPLICABILITY

According to the present invention, it is possible to perform both theformation of a Cu diffusion preventing film and the embedding of a Cufilm using the medium of a supercritical state. Since the solubility ofthe precursor compound containing metal, for example, Cu, or Ta, is highand the medium of a supercritical state has good mobility and highdiffusibility, it is possible to perform the formation of the Cudiffusion preventing film and the embedding of the Cu film in a veryfine pattern.

1. A substrate processing method comprising: a first step of processinga substrate by supplying a first processing medium containing a firstmedium of a supercritical state onto the substrate; a second step offorming a Cu diffusion preventing film on the substrate by supplying asecond processing medium containing a second medium of a supercriticalstate onto the substrate; and a third step of forming a Cu film on thesubstrate by supplying a third processing medium containing a thirdmedium of a supercritical state onto the substrate.
 2. The substrateprocessing method according to claim 1 characterized in that the Cudiffusion preventing film is made of any of a film of a metal, a film ofa nitride of the metal, and a laminated film of the metal film and thenitride film.
 3. The substrate processing method according to claim 2characterized in that the second step comprises either a step of formingthe metal film or the nitride film or a step of forming the laminatedfilm of the metal film and the nitride film.
 4. The substrate processingmethod according to claim 1 characterized in that the second medium ofthe supercritical state is made of any of CO2 of a supercritical state,a nitriding compound of a supercritical state, and a mixture of the CO2and the nitriding compound.
 5. The substrate processing method accordingto claim 4 characterized in that the nitriding compound is NH3.
 6. Thesubstrate processing method according to claim 1 characterized in thatthe second processing medium is made by adding a precursor compoundcontaining a metal to the second medium of the supercritical state. 7.The substrate processing method according to claim 6 characterized inthat the metal is Ta.
 8. The substrate processing method according toclaim 7 characterized in that the precursor compound containing themetal is chosen from a group including TaF5, TaCl5, TaBr5, and TaI5. 9.The substrate processing method according to claim 7 characterized inthat the precursor compound containing the metal is an organic metalliccompound.
 10. The substrate processing method according to claim 9characterized in that the organic metallic compound is either(C5H5)2TaH3 or (C5H5)2TaCl3.
 11. The substrate processing methodaccording to claim 1 characterized in that the second step comprises astep of removing, after the Cu diffusion preventing film is formed, thesecond processing medium and a by-product on a surface of the substrateby the second medium of the supercritical state.
 12. The substrateprocessing method according to claim 1 characterized in that the thirdmedium of the supercritical state is CO2 of a supercritical state. 13.The substrate processing method according to claim 1 characterized inthat the third processing medium is made by adding a copper-containingprecursor compound to the third medium of the supercritical state. 14.The substrate processing method according to claim 13 characterized inthat the copper-contained precursor compounds is any of Cu⁺²(hexafluoroacetylacetonate)₂, Cu⁺² (acetylacetonate)₂ or Cu⁺²(2,2,6,6-tetramethyl-3,5-heptanedione)₂.
 15. The substrate processingmethod according to claim 13 characterized in that the copper-containedprecursor compound is a compound containingCu⁺¹(hexafluoroacetylacetonate) and scillirolefinligand, thescillirolefinligand being any chosen from among a group includingtrimethylvinylsilane (tmvs), allyl-.oxytrimethylscillire (aotms),dimethylacetylene(2-butyne), 2-methyl-1-hexine-3-in (MHY),3-hexine-2,5-dimethoxy(HDM), 1,5-cyclooctadiene(1,5-COD), andvinyltrimethoxylene (VTMOS).
 16. The substrate processing methodaccording to claim 1 characterized in that the third step furthercomprises a step of removing the third processing medium and aby-product on a surface of the substrate by the third medium of thesupercritical state after the Cu film is formed.
 17. The substrateprocessing method according to claim 1 characterized in that the firstmedium of the supercritical state is CO2 of a supercritical state. 18.The substrate processing method according to claim 1 characterized inthat the first processing medium is made by adding an etching agent tothe first medium of the supercritical state.
 19. The substrateprocessing method according to claim 18 characterized in that theetching agent is any of a chelating agent, a halogenated compound, anacid, or an amine.
 20. The substrate processing method according toclaim 1 characterized in that, in the first step, a Cu oxide film formedon a Cu surface on the substrate is removed by the first processingmedium.
 21. The substrate processing method according to claim 1characterized in that the first step further comprises a step ofremoving the first processing medium and a by-product on a surface ofthe substrate by the first medium of the supercritical state after thesubstrate is processed by the first processing medium.
 22. The substrateprocessing method according to claim 1 characterized in that the firststep, the second step, and the third step are performed in a processingcontainer which processes the substrate.
 23. The substrate processingmethod according to claim 1 characterized in that the first step isperformed in a first processing container which processes the substrate,the second step is performed in a second processing container, and thethird step is performed in a third processing container.
 24. Thesubstrate processing method according to claim 1 characterized in thatthe first step and the second step are performed in a processingcontainer which processes the substrate, and the third step is performedin another processing container.
 25. The substrate processing methodaccording to claim 1 characterized in that the first step is performedin a processing container which processes the substrate, and the secondstep and the third step are performed in another processing container.26. A semiconductor device manufacturing method characterized in thatthe semiconductor device manufacturing method includes the substrateprocessing method according to claim 1.